For me two things happened right around the same time. I moved to the Bay Area for a job opportunity, but rents being what they are, I had to shack up in a large house with lots of roomies because it was all I could find on short notice in my price range. The majority of my housemates were cool, but one was an out and out troon. Like most of you, I am a live and let live guy, so I was willing to give him a chance. But he insisted on walking around the house naked, and when I would say "hey man I'm really not comfortable with you sitting on the furniture with your stinkditch" I was told that I was the one with the problem. Was able to get out of there in a few months, thankfully, but that shit made me realize that what was once leftism was turning into a never ending cycle of woker and woker idpol.
The second thing that happened right around then is that Terese Nielsen, an artist for Magic the Gathering and various other fantasy/sci-fi works, got publicly excoriated and excommunicated for the crime of liking some Qanon tweets. Somehow this action spun out into a tale of transphobia because, uh, reasons? You literally cannot find anything of hers, via twitter or blog posts or anything, that suggests she is or was ever anti-tranny, but because a few retards on Reddit started insisting that it was so, it became the accepted truth. The sheer gall of people lying, over and over, about what anyone with half a brain could tell was a wad of bullshit is what got me to really investigate the cult of troon and realize how fucked up most of them were.